1. Field of the Invention
The present invention relates to a xerographic fuser architecture which provides two separate fuser rolls about a central common pressure roll, each fuser roll being designed for a different application, i.e., color fusing or black and white fusing requirements.
2. Description of Related Art
Most known fuser roll architectures utilize a single fuser roll in conjunction with a pressure roll. If used for a single application, such as black and white printing, the fuser roll design can accommodate the needs of the particular printing that is to be done. For example, typically customer preference for color xerographic prints is a high gloss finish. This usually requires the use of a smooth, conformable fuser roll operating at a high temperature and having a long-dwell nip. However, customer preference for black and white xerographic copies is a matte finish, which requires a different fuser design and operating parameters. In a color copier which can provide either color or black and white xerographic prints, it has been customary to compromise the needs of these different operating parameters and design criteria into a design which can adequately provide moderate capabilities of either type print.
There are known fusing systems which provide multiple fusers such as U.S. Pat. Nos. 4,928,148; 5,019,869; 4,791,447; and 5,053,828.
There is a need for a multiple fuser system which can accommodate fusing of a developed image on either side of a copy substrate without complicated inversion apparatus. There also is a need for a multiple fuser roll system which can accommodate images having varying fusing characteristics with minimal power requirements.